The Initial Corrosion Characteristic Research Of Q235Steel In Simulated Typical Marine Atmospheric Environment

It has important theoretical significance and extensive application value to studythe process of atmospheric corrosion of carbon steel and understand the corrosioncharacteristics in different environment for reasonable selection of materials,providing the corresponding protective measures, prolonging the service life ofequipments and components.In this paper, detection system is designed to study the atmospheric corrosion ofQ235steel. Electrochemical noise resistances acquired in different simulatedatmosphere were used to study corrosion behaviors of Q235steel. The results showedthat the effect of the main ions which [Cl-]=0.1mol/L,[NO3-]=0.01mol/L,[SO42-]=0.01mol/L, the corrosion rate of Q235steel in the three kinds of simulationenvironment increases with the increasing of the relative humidity respectively. As weall know, the relative humidity would affect the thickness of the liquid film thicknesson the surface of the samples, Carbon steel wire beam electrode were used to explorethe heterogeneous distribution of the specimen within different liquid film thickness.With the application of atmospheric corrosion of Q235steel detection system,this paper presents the application of wavelet noise resistance (Rcd) acquired fromelectrochemical noise analysis to evaluate the early formation and development law ofcorrosion products within different simulated marine atmospheric environments. Theexperimental results from noise resistances (Rn) showed that the corrosion rateincreased with the exposure time. The experimental results from noise resistances andsurface corrosion morphology showed that the corrosion rate was larger in the greaterspray concentration environment. Rnand Rcdclose to2Hz correlated well in the twosimulated atmosphere conditions. Wavelet noise resistance is supposed to be effectiveto analysis the atmospheric corrosion damage to Q235steel in marine environment.Image processing method was applied to analyze the corrosion morphology ofQ235steel. The median filtering method was used to remove the effect of noise inthe image. The wavelet packet–based image analysis method was applied todecompose the images and energy of sub-images were extracted as characteristicinformation. The results showed that the corrosion levels of Q235steel specimenscan be reflected by energy changes.